An 86-year-old man was assaulted by left-wing extremists at a solidarity vigil for three kidnapped Israeli teens in Germany last week.

The "Bring Back Our Boys" rally took place in the northern German city of Hamburg, and was organized by the Young Forum of the German-Israel Society and the Hamburg for Israel network, according to the Juedische Allgemeine, Germany's largest Jewish newspaper.

One witness described to Arutz Sheva how the elderly man was shoved violently to the ground by counter-demonstrators from the radical anti-globalization group ATTAC.

The victim - who has asked not to be identified - was first verbally harassed by a man holding a placard calling for a boycott of Israeli goods. After a brief verbal exchange the protester suddenly "pushed the old man very hard", causing him to fall and sustain a head injury, said Ina Dinslage, who was herself taking part in the vigil.

The violent anti-Israel activist then kicked the man's 52-year-old daughter as she came to his aid.

Bystanders called an ambulance after noting that the elderly man "was bleeding on his head and couldn't really move"; the victim is still in hospital nearly a week later.

A complaint has been lodged with the police.

"This kind of pure hatred against Israel not only exists in Germany but is expressed in violent assaults," the head of the Central Council of Jews in Germany told Juedische Allgemeine.

Dieter Graumann called on police to "quickly apprehend the perpetrators and bring them to justice."